I dropped out of high school on my first day of 9th grade when I was 15 years old. I had been previously emancipated so I could legally do so. 
I have yet to go back and get my GED, though I would like to soon. 
I don't know exactly how high my education level is, I had a really tough childhood and my parents spilt for good when I was 8 years old. I was in third grade and everyone around my watched as my grades spiraled down and stayed there. This was a time period where they would promote you to the next grade whether you actually earned it or not, it was unheard of to actually be kept back in elementary school when I was there, early 90's. I believe if they had held me back or if some teacher at some point even just pulled me aside and asked me how things were at home, everything would have been different. I was crying out for someone to care and instead teacher after teacher in grade after grade let me fall through the cracks or spent their energy getting mad at me for consistently not bringing in homework because my mother would keep me up until 11pm or later every night.
By the time I was 15 I had just entered 9th grade because the school system finally started holding me back in Juinor High. At that point I just left.
I got married at 15 as well, to an older man, who I'm still married to today and he holds a BA in Computer Science and did some college for Astronomy. 
Even though he has the BA though, he has never used it in a career sense. He is a movie theater projectionist manager, and a mailman for USPS. 
Just because I dropped out doesn't mean I stopped learning though. I have learned more on my own and with my husband than I ever learned in a school setting and other than Math I feel I will probably soar through the GED testing. Our children are home schooled now as well. 
I used to type horribly and mis-spell nearly every word I wrote, it was awful. But I've always been well spoken and told that I seemed mature for my age.
It's an interesting subject. I do think that there must be some connection between people who are more inclined to be self-sufficient and general smarts. 
I belong to some other forums that are full of people who don't know how to talk or type. The majority here are well spoken/written and considering that in most cases that is the only impression you have of those people, it's natural to assume they must be well educated. 
Only one other forum I belong to has this high of number of "brainy" people, and it's a large natural parenting forum, go figure.